Bug in src/regioniterator.jl

[LilithHafner]

StyledStrings.jl/src/regioniterator.jl

Line 30 in 74e7135

```jldoctest; setup = :(import AnnotatedString; import StyledStrings.eachregion)

import AnnotatedString does not make sense. I think this would get caught in CI if it built docs.

[tecosaur]

Hmm, this might be caught if the docs could actually build themselves.